Heat oven to 350º F. Combine the egg, ricotta, Parmesan, oil, thyme, and 1/4 teaspoon each salt and pepper. Pour into a buttered 2-cup oven-safe dish. Bake until golden and puffy, 25 to 30 minutes.
Serve with toasts or crudités.
Tip: Spice this recipe up with a pinch of crushed red pepper sprinkled over the ricotta before baking.